fix(player): 收紧图片与快速切集资源占用

lib/core/data/services/playback_session.dart

@@ -81,6 +81,8 @@ class PlaybackSession extends ChangeNotifier {
   // Includes initialization and asynchronous disposal, until native release ends.
   int get livePlayerCount => _live.length;
   int? get preloadedIndex => _next?.prepared == true ? _next?.index : null;
+  int? get previousPreloadedIndex =>
+      _previous?.prepared == true ? _previous?.index : null;
   Future<void> get playbackSettled => _operations;
   Future<void> get preloadSettled => _preloadTask;
 

lib/core/data/services/sprite_thumbnail_axis.dart

@@ -9,7 +9,7 @@ import '../../config/app_config.dart';
 import 'sprite_thumbnail_asset_loader.dart';
 
 const Duration spriteVttCacheTtl = Duration(minutes: 10);
-const int spriteImageCacheCapacity = 2;
+const int spriteImageCacheCapacity = 1;
 
 /// 单个 VTT cue 对应的 sprite 裁剪区域。
 class SpriteThumbnailCue {
@@ -148,7 +148,6 @@ class SpriteThumbnailAxisService extends ChangeNotifier
   final Set<String> _failedSprites = {};
   bool _disposed = false;
 
-  @visibleForTesting
   int get spriteCacheSize => _spriteCache.length;
 
   @visibleForTesting
@@ -156,7 +155,7 @@ class SpriteThumbnailAxisService extends ChangeNotifier
       .map((url) => Uri.tryParse(url)?.pathSegments.lastOrNull ?? url)
       .toList();
 
-  /// 播放器就绪时预取当前 cue 与相邻 sprite，拖动帧不触发网络或解码。
+  /// 播放器就绪时预取当前 cue；容量大于 1 时顺带预取相邻 sprite。
   @override
   Future<void> prepareAt(String? thumbnailsUrl, Duration position) async {
     final url = _normalizeUrl(thumbnailsUrl);
@@ -269,6 +268,7 @@ class SpriteThumbnailAxisService extends ChangeNotifier
     if (current == null) return const [];
     final index = axis.cues.indexOf(current);
     final candidates = <SpriteThumbnailCue>[current];
+    if (spriteCacheCapacity <= 1) return candidates;
     for (final direction in const [1, -1]) {
       for (var step = 1; step < axis.cues.length; step++) {
         final neighborIndex = index + direction * step;

lib/core/widgets/remote_image.dart

@@ -5,6 +5,24 @@ import 'package:flutter/material.dart';
 import '../config/app_config.dart';
 import '../theme/app_colors.dart';
 
+const int _minImageDecodePixels = 96;
+const int _maxImageDecodePixels = 2048;
+
+/// 将布局逻辑尺寸换算成有限像素尺寸，兼顾小头像和全屏首帧。
+int resolveImageDecodePixels(double? logicalExtent, double devicePixelRatio) {
+  final ratio = devicePixelRatio.isFinite && devicePixelRatio > 0
+      ? devicePixelRatio
+      : 1.0;
+  final extent =
+      logicalExtent != null && logicalExtent.isFinite && logicalExtent > 0
+      ? logicalExtent
+      : 120.0;
+  return (extent * ratio)
+      .ceil()
+      .clamp(_minImageDecodePixels, _maxImageDecodePixels)
+      .toInt();
+}
+
 /// 封面图统一入口：后端给的是相对路径，这里补服务地址并处理加载失败。
 class RemoteImage extends StatelessWidget {
   const RemoteImage(
@@ -17,6 +35,8 @@ class RemoteImage extends StatelessWidget {
     this.fallbackIconKey,
     this.fallbackAspectRatio,
     this.fallbackColor = AppColors.raised,
+    this.decodeWidth,
+    this.decodeHeight,
   });
 
   final String path;
@@ -27,21 +47,56 @@ class RemoteImage extends StatelessWidget {
   final Key? fallbackIconKey;
   final double? fallbackAspectRatio;
   final Color fallbackColor;
+  final int? decodeWidth;
+  final int? decodeHeight;
 
   @override
   Widget build(BuildContext context) {
     final url = AppConfig.mediaUrl(path);
     if (url.isEmpty) return _fallback(brand: showFallbackIcon);
-    return Image.network(
-      url,
-      width: width,
-      height: height,
-      fit: fit,
-      gaplessPlayback: true,
-      errorBuilder: (_, _, _) => _fallback(brand: showFallbackIcon),
-      frameBuilder: (context, child, frame, wasSynchronouslyLoaded) {
-        if (wasSynchronouslyLoaded || frame != null) return child;
-        return _fallback(brand: showFallbackIcon);
+    return LayoutBuilder(
+      builder: (context, constraints) {
+        final pixelRatio = MediaQuery.devicePixelRatioOf(context);
+        final layoutWidth = constraints.hasBoundedWidth
+            ? constraints.maxWidth
+            : width;
+        final aspectRatio =
+            fallbackAspectRatio != null &&
+                fallbackAspectRatio!.isFinite &&
+                fallbackAspectRatio! > 0
+            ? fallbackAspectRatio
+            : null;
+        final inferredHeight = constraints.hasBoundedHeight
+            ? constraints.maxHeight
+            : height ??
+                  (layoutWidth != null && aspectRatio != null
+                      ? layoutWidth / aspectRatio
+                      : null);
+        final cacheWidth =
+            decodeWidth ?? resolveImageDecodePixels(layoutWidth, pixelRatio);
+        final cacheHeight =
+            decodeHeight ??
+            (inferredHeight == null
+                ? null
+                : resolveImageDecodePixels(inferredHeight, pixelRatio));
+        return Image.network(
+          url,
+          width: width,
+          height: height,
+          fit: fit,
+          cacheWidth: cacheWidth
+              .clamp(_minImageDecodePixels, _maxImageDecodePixels)
+              .toInt(),
+          cacheHeight: cacheHeight
+              ?.clamp(_minImageDecodePixels, _maxImageDecodePixels)
+              .toInt(),
+          gaplessPlayback: true,
+          errorBuilder: (_, _, _) => _fallback(brand: showFallbackIcon),
+          frameBuilder: (context, child, frame, wasSynchronouslyLoaded) {
+            if (wasSynchronouslyLoaded || frame != null) return child;
+            return _fallback(brand: showFallbackIcon);
+          },
+        );
       },
     );
   }

lib/pages/player/player_logic.dart

@@ -93,6 +93,9 @@ class PlayerLogic extends ChangeNotifier {
   String selectedQuality = 'AUTO';
   Duration? _qualitySeek;
   int pageRequest = 0;
+  int? _pendingSelectionIndex;
+  int? _pendingSelectionRevision;
+  Future<void>? _selectionDrain;
   bool muted = false;
   double playbackSpeed = 1.0;
   bool stoppedAtFeedEnd = false;
@@ -957,6 +960,37 @@ class PlayerLogic extends ChangeNotifier {
     );
   }
 
+  /// 翻页入口使用 single-flight：执行中的切集不被重复排队，只保留最新目标。
+  Future<void> requestEpisodeSelection(int index, {int? revision}) {
+    if (_disposed || index < 0 || index >= sessionEpisodes.length) {
+      return Future<void>.value();
+    }
+    _pendingSelectionIndex = index;
+    _pendingSelectionRevision = revision;
+    return _selectionDrain ??= _drainEpisodeSelections();
+  }
+
+  Future<void> _drainEpisodeSelections() async {
+    try {
+      while (!_disposed) {
+        final index = _pendingSelectionIndex;
+        if (index == null) break;
+        final revision = _pendingSelectionRevision;
+        _pendingSelectionIndex = null;
+        _pendingSelectionRevision = null;
+        await selectEpisode(index, revision: revision);
+      }
+    } finally {
+      _selectionDrain = null;
+      final index = _pendingSelectionIndex;
+      if (!_disposed && index != null) {
+        unawaited(
+          requestEpisodeSelection(index, revision: _pendingSelectionRevision),
+        );
+      }
+    }
+  }
+
   Future<void> selectEpisode(int index, {int? revision}) async {
     final feedRevisionAtStart = revision ?? feedRevision;
     final request = ++pageRequest;

lib/pages/player/player_view.dart

@@ -353,6 +353,28 @@ class _PlayerPageState extends State<PlayerPage>
     );
   }
 
+  Future<void> _selectPage(int index) async {
+    await logic.requestEpisodeSelection(index);
+    if (!mounted || logic.session.currentIndex != index) return;
+    await logic.session.preloadSettled;
+    if (!mounted || logic.session.currentIndex != index) return;
+    _logResourceWatermark();
+  }
+
+  void _logResourceWatermark() {
+    if (!kDebugMode) return;
+    final imageCache = PaintingBinding.instance.imageCache;
+    debugPrint(
+      '[player-resources] '
+      'slots=${logic.session.livePlayerCount} '
+      'warmNext=${logic.session.preloadedIndex ?? '-'} '
+      'warmPrevious=${logic.session.previousPreloadedIndex ?? '-'} '
+      'sprites=${_spriteAxisService.spriteCacheSize} '
+      'imageCacheBytes=${imageCache.currentSizeBytes} '
+      'imageCacheCount=${imageCache.currentSize}',
+    );
+  }
+
   void _setScrubbing(bool value) {
     if (!mounted) return;
     if (_scrubbing == value) return;
@@ -507,7 +529,7 @@ class _PlayerPageState extends State<PlayerPage>
             onPageChanged: (position) {
               final index = indices[position];
               widget.onDramaChanged?.call(logic.queue.entryAt(index).drama);
-              unawaited(logic.selectEpisode(index));
+              unawaited(_selectPage(index));
               if (position >= indices.length - 3) {
                 final loadMore = widget.onLoadMore;
                 if (loadMore != null) unawaited(loadMore());

lib/pages/player/widgets/player_opening_frame.dart

@@ -7,6 +7,7 @@ import 'package:flutter/material.dart';
 import '../../../core/config/app_config.dart';
 import '../../../core/data/services/sprite_thumbnail_axis.dart';
 import '../../../core/theme/app_colors.dart';
+import '../../../core/widgets/remote_image.dart';
 import 'scrub_preview_card.dart';
 
 enum PlayerOpeningFallback { handoff, poster, thumbnails, black }
@@ -149,12 +150,25 @@ class _PlayerOpeningFrameState extends State<PlayerOpeningFrame> {
     children: [
       const ColoredBox(color: AppColors.mediaBlack),
       if (_hasPoster)
-        Image.network(
-          AppConfig.mediaUrl(widget.posterUrl!.trim()),
-          key: const Key('player-opening-poster'),
-          fit: widget.fit,
-          gaplessPlayback: true,
-          errorBuilder: (_, _, _) => _handlePosterError(),
+        LayoutBuilder(
+          builder: (context, constraints) {
+            final pixelRatio = MediaQuery.devicePixelRatioOf(context);
+            return Image.network(
+              AppConfig.mediaUrl(widget.posterUrl!.trim()),
+              key: const Key('player-opening-poster'),
+              fit: widget.fit,
+              cacheWidth: resolveImageDecodePixels(
+                constraints.maxWidth,
+                pixelRatio,
+              ),
+              cacheHeight: resolveImageDecodePixels(
+                constraints.maxHeight,
+                pixelRatio,
+              ),
+              gaplessPlayback: true,
+              errorBuilder: (_, _, _) => _handlePosterError(),
+            );
+          },
         )
       else
         _spriteOrBlack(),

test/playback/sprite_thumbnail_axis_test.dart

@@ -75,7 +75,9 @@ void main() {
     expect(axis.cues, isEmpty);
   });
 
-  testWidgets('should_keep_only_two_decoded_sprites_in_lru', (tester) async {
+  testWidgets('should_keep_one_sprite_and_reload_after_eviction', (
+    tester,
+  ) async {
     final loader = _FakeSpriteLoader(vtt: _spriteVtt);
     final service = SpriteThumbnailAxisService(
       loader: loader,
@@ -84,20 +86,37 @@ void main() {
     addTearDown(service.dispose);
 
     await service.prepareAt('https://cdn.test/thumbnails.vtt', Duration.zero);
-    expect(service.spriteCacheSize, 2);
-    expect(
-      service.spriteCacheKeys,
-      containsAll(['sprite_001.jpg', 'sprite_002.jpg']),
-    );
-
     await service.prepareAt(
       'https://cdn.test/thumbnails.vtt',
       const Duration(milliseconds: 2500),
     );
+    await service.prepareAt(
+      'https://cdn.test/thumbnails.vtt',
+      const Duration(milliseconds: 3500),
+    );
 
-    expect(service.spriteCacheSize, 2);
-    expect(service.spriteCacheKeys, contains('sprite_002.jpg'));
-    expect(service.spriteCacheKeys, isNot(contains('sprite_001.jpg')));
+    expect(service.spriteCacheSize, 1);
+    expect(service.spriteCacheKeys, ['sprite_003.jpg']);
+    expect(loader.images[0].debugDisposed, isTrue);
+    expect(loader.images[1].debugDisposed, isTrue);
+    expect(loader.images[2].debugDisposed, isFalse);
+    expect(
+      service.cachedFrameAt(
+        'https://cdn.test/thumbnails.vtt',
+        const Duration(milliseconds: 3500),
+      ),
+      isNotNull,
+    );
+
+    await service.prepareAt('https://cdn.test/thumbnails.vtt', Duration.zero);
+    expect(service.spriteCacheSize, 1);
+    expect(service.spriteCacheKeys, ['sprite_001.jpg']);
+    expect(loader.images[2].debugDisposed, isTrue);
+    expect(loader.images[3].debugDisposed, isFalse);
+    expect(
+      service.cachedFrameAt('https://cdn.test/thumbnails.vtt', Duration.zero),
+      isNotNull,
+    );
   });
 
   testWidgets('should_cache_vtt_and_retry_once_after_403', (tester) async {
@@ -229,6 +248,7 @@ class _FakeSpriteLoader implements SpriteThumbnailAssetLoader {
   final List<Object>? vttResponses;
   int vttCalls = 0;
   final List<String> spriteCalls = [];
+  final List<ui.Image> images = [];
 
   @override
   Future<String?> loadVtt(Uri uri) async {
@@ -244,6 +264,7 @@ class _FakeSpriteLoader implements SpriteThumbnailAssetLoader {
   Future<SpriteThumbnailDecodedImage?> loadSprite(Uri uri) async {
     spriteCalls.add(uri.pathSegments.last);
     final image = await _createImage(320, 180);
+    images.add(image);
     return SpriteThumbnailDecodedImage(
       image: image,
       originalWidth: 320,

test/player/player_logic_test.dart

@@ -422,6 +422,42 @@ void main() {
     await _drain(logic);
   });
 
+  test('should_coalesce_rapid_page_selection_and_keep_pool_bounded', () async {
+    final factory = _RecordingFactory();
+    final playback = FakePlaybackRepository();
+    final logic = _logic(FakeWatchHistory(), playback: playback);
+    logic.attach(
+      PlayerPage(
+        drama: _drama('rapid', numbers: const [1, 2, 3, 4, 5, 6]),
+        initialIndex: 0,
+      ),
+      isMounted: () => true,
+    );
+    logic.start(factory: factory.create, coordinator: PlaybackCoordinator());
+    await _drain(logic);
+
+    await Future.wait([
+      for (var index = 1; index <= 5; index++)
+        logic.requestEpisodeSelection(index),
+    ]);
+    await _drain(logic);
+
+    expect(logic.session.currentIndex, 5);
+    expect(playback.requests, containsAll(['rapid-1', 'rapid-2', 'rapid-6']));
+    expect(playback.requests, isNot(contains('rapid-3')));
+    expect(playback.requests, isNot(contains('rapid-4')));
+    expect(playback.requests, isNot(contains('rapid-5')));
+    expect(logic.session.livePlayerCount, lessThanOrEqualTo(3));
+    expect(factory.live, lessThanOrEqualTo(3));
+
+    await logic.requestEpisodeSelection(0);
+    await _drain(logic);
+    expect(logic.session.currentIndex, 0);
+
+    logic.dispose();
+    await _drain(logic);
+  });
+
   group('surface flags', () {
     test('should_set_immersive_when_picture_in_picture_callback_fires', () async {
       final factory = _RecordingFactory();

test/player/player_opening_frame_test.dart

@@ -64,6 +64,38 @@ void main() {
     expect(loader.vttCalls, 0);
   });
 
+  testWidgets('should_decode_fullscreen_poster_at_screen_width', (
+    tester,
+  ) async {
+    final service = SpriteThumbnailAxisService(loader: _FakeSpriteLoader());
+    addTearDown(service.dispose);
+
+    await tester.pumpWidget(
+      MaterialApp(
+        home: MediaQuery(
+          data: const MediaQueryData(devicePixelRatio: 3),
+          child: Center(
+            child: SizedBox(
+              width: 390,
+              height: 844,
+              child: PlayerOpeningFrame(
+                posterUrl: 'https://cdn.test/poster.jpg',
+                thumbnailsUrl: '',
+                spriteSource: service,
+              ),
+            ),
+          ),
+        ),
+      ),
+    );
+
+    final image = tester.widget<Image>(
+      find.byKey(const Key('player-opening-poster')),
+    );
+    final provider = image.image as ResizeImage;
+    expect(provider.width, 1170);
+  });
+
   testWidgets('should_return_no_opening_frame_when_thumbnails_is_empty', (
     tester,
   ) async {

test/player/remote_image_decode_test.dart

@@ -0,0 +1,35 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:fruitshorts/core/widgets/remote_image.dart';
+
+void main() {
+  test('should_bound_layout_pixels_for_small_and_large_extents', () {
+    expect(resolveImageDecodePixels(12, 3), 96);
+    expect(resolveImageDecodePixels(120, 3), 360);
+    expect(resolveImageDecodePixels(4000, 3), 2048);
+  });
+
+  testWidgets('should_decode_grid_cover_at_layout_width_times_dpr', (
+    tester,
+  ) async {
+    await tester.pumpWidget(
+      MaterialApp(
+        home: MediaQuery(
+          data: const MediaQueryData(devicePixelRatio: 3),
+          child: Center(
+            child: SizedBox(
+              width: 120,
+              height: 160,
+              child: RemoteImage('/files/grid-cover.jpg'),
+            ),
+          ),
+        ),
+      ),
+    );
+
+    final image = tester.widget<Image>(find.byType(Image));
+    final provider = image.image as ResizeImage;
+    expect(provider.width, 360);
+    expect(provider.height, 480);
+  });
+}